package com.cw.jeeyt.common;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.sql.Blob;
import java.sql.CallableStatement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.apache.ibatis.type.BaseTypeHandler;
import org.apache.ibatis.type.JdbcType;

/**
 * className:ConvertBlobTypeHandler
 *
 * 自定义typehandler，解决mybatis存储blob字段后，出现乱码的问题
 * 配置mapper.xml：
 * <result typeHandler="com.cw.jeeyt.common.ConvertBlobTypeHandler"/>
 *
 * @author pengyh
 * @version 1.0.0
 * @date 2014-07-09 11:15:23
 */
public class ConvertBlobTypeHandler extends BaseTypeHandler<String> {
    //###指定字符集    
    private static final String DEFAULT_CHARSET = "utf-8";

    @Override
    public void setNonNullParameter(PreparedStatement ps, int i, String parameter, JdbcType jdbcType)
    throws SQLException {
        ByteArrayInputStream bis = null;
        try {
            //###把String转化成byte流    
            bis = new ByteArrayInputStream(parameter.getBytes(DEFAULT_CHARSET));
            ps.setBinaryStream(i, bis, parameter.length());
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException("Blob Encoding Error!");
        } finally {
            try {
                bis.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    @Override
    public String getNullableResult(ResultSet rs, String columnName) throws SQLException {
        Blob blob = rs.getBlob(columnName);
        byte[] returnValue = null;
        if (null != blob) {
            returnValue = blob.getBytes(1, (int) blob.length());
            try {
                //###把byte转化成string    
                return new String(returnValue, DEFAULT_CHARSET);
            } catch (UnsupportedEncodingException e) {
                return null;
            }
        }
        return "";
    }

    @Override
    public String getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
        Blob blob = cs.getBlob(columnIndex);
        byte[] returnValue = null;
        if (null != blob) {
            returnValue = blob.getBytes(1, (int) blob.length());
            try {
                return new String(returnValue, DEFAULT_CHARSET);
            } catch (UnsupportedEncodingException e) {
                throw new RuntimeException("Blob Encoding Error!");
            }
        }
        return "";
    }

    @Override
    public String getNullableResult(ResultSet arg0, int arg1) throws SQLException {
        return null;
    }
}   
